Telephone-exchange system.



G. BABCOCK.

TELEPHONE EXCHANGE SYSTEM.

APPLI CATION FILED Aue.8. 1913.

1,230,835. Patented June 26, 191?.

am G'arrisonfidcock WGW UNITED STATES PATENT OFFICE.

GARRISON BABCOCK, OF. CHICAGO, ILLINOIS, ASSIGNOR TO TELECI-IRONOMETER COM- PANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. Patented June 26, 191".

Original application filed February 17, 1910, Serial No. 544,429. Divided and this application filed August 8, 1913. Serial No. 783,661.

T 0 all whom it'mag concern:

Be it known that I, GARRrsoN 'BABoooK,

a citizen of the United States, residing at Chicago, in the'county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to service meters for telephone exchange systems, and has reference particularly to that class of serv: ice meters in which the metering mechanism is located at the substations.

It is an object of my invention to provide a meter of the class referred to of such a nature that the meter is under the joint control of the subscriber and of the apparatus located at the exchange which apparatus is controlled by the called subscriber in answering the call. My invention refers particularly to such a combina tion of parts that the operation of registering a call initiated at any substation is accomplished by means of the operation at such substation of the mechanism ordinarily used in calling the central exchange.

' After connection has been madeby the operator at the exchange with the calling line and such connection has been'e'xtended to the called line, response on the "part of the called subscriber causes operation of relay mechanism associated with the cord circuit employed in making the connection in such a manner as to reverse the-polarity of the current supplied to the I answering end of the cord circuit and this manner apparatus is actuated at the-calling substation which apparatus by its operation serves to reset the register ready for registering another call.

In carrying out my invention I preferqto employ at the substation a polarized relay which is responsive to a reversal in current direction as a result of which-the resetting magnet is actuated when the polarized re: lay is operated.-

After having been properly reset to be actuated the meter may be; operated either by the mechanical operation of the switch hook or may be electrically operated by a circuit closed at the motion] of the switch hook from its talking to its normal position.

This case is a division of my'previous application Serial No. 54:4,429 filed Feb. 17, 1910.

In the drawings: t I

The accompanying illustration is a diagrammati'c drawing showing the telephone system complete with the apparatus at one of the substations in its talking condition while the apparatus at the other substation is shown in its normal or resting condition.

In illustrating my invention, I have shown the substation A connected by line wires 1 and 2 with the exchange, the line circuit there terminating in the tip and sleeve springs 3 and 4 respectively of the line jack J. The springs 3 and 4 normally make contact with the contact springs 5 and 6 respectively. The spring 5 is connected with the winding of the line relay 7, the other terminal of which is connected by wire 8 with the negative'pole of the battery B. The spring 6 is connected by wire 9 with the positive pole of battery B.

The register mechanism 22 is adapted to be operated by a lever 23 pivoted at 24 by means of a pawl 25 pivoted at 26 to such lever. The lever 23 also serves as a polarized armature for the resetting magnet 31 of the registering mechanism, as a result of which when the magnet 31 is properly energized the lever 23 is moved forcibly downward thus resetting the pawl 25 in position to subsequently operate the registering mechanism. This motion of the lever 23 releases the spring 32 which is comparatively stiff and permits it ,to engage the contact 31' carried by the contact spring 33.

At the substations there is arranged the subscribers telephone set comprising the transmitter T and the receiver R which is adapted to be hung on the hook 19; The

latter is pivoted at the point 29 and cooperates with a block of insulating material 18 resting on the spring 18, which when in its operative position engages the contact 17 and when depressed, by hanging the receiver on the hook, engages the contact 18". The induction coil is indicated by 12 and one extremity of the primary winding thereof connected by wire 20 with contact 17 the other extremity of said coil indicated by 21 to the transmitter, to one terminal of the winding of the resetting magnet 31 at 21 to contact spring 33.

An operating magnet 85 is provided for actuating the registering mechanism by rotating the lever 23 on its pivot after it has been set into the operative position by the magnet 31. The energizing of said operating magnet havingbeen controlled by the moving of the switch or hook 19.

The winding of the magnet 85 is connected between the line conductor 1 and the spring 18 adapted to be engaged by the spring 18 when the hook switch is in its normal position. Switch springs 86 and 87 are included in this path for the purpose of interrupting the circuit of the magnet 85 when the lever 23 is moved downward at its right hand end by the energization of the magnet to advance the registering mechanism 22. The springs 86 and 87 which are in contact when the lever 23 is in its set position, are so conformed at their upper ends as to engage rollers 88 and 89 carried by the right hand end of the lever 23. hen the lever is in its set position the spring 86 engages the roller 88 but the engagement between the springs 86 and 87 serve. to lift thespring 87 from engagement with the roller 89. .VVhen, however, the lever 23 is moved downward at its right hand end the roller 89 comes into engagement with the spring 87 while the roller 88 is moved from engagement with the spring 86 thus allowing the spring 86 to spring away to the left from engagement with the spring 87 and open the circuit through the energizing winding of the magnet 85. The conformation of the upper end of the spring 87 serves at this time to retain the lever 23 in the position to which it has been moved by the magnet 85.

The springs32 and 33 are also conformed at their upper ends to engagethe rollers 32 and 33 which are carried by the left hand end of the lever 23. The spring 33 serving, when the lever 23 is moved downward at its left hand end, to lock the lever in such position until it is positively operated by means of the magnet 85.

The :centers of the rollers .32 and 33 and the free ends of the springs 32 and 33 are so disposed that when the lever 23 is in its upper or actuated position no tension is exerted by said springs to throw the lever in one direction or the other. However when the lever 23 is retracted to its resetting position the rollers permit the engagement of the spring 32 and the contact 31.

The transmitter and primary winding of the induction coil 12 are included between the winding 31 and the spring 17- of the hook switch so that there is no interruption inthe path of the current through said winding when the magnet 31 is short circuited by the closing of the contacts 31" and 32. Ringer '90 may be connected between the lined conductor 1 and the spring 87 with a condenser interposed to prevent the flow ofsteady current.

The resetting magnet 31 is connected between the line wire 1 and the wire 21 and the contact springs 32 and 33 are connected to the terminals of the resetting magnet as indicated sothat when the lever 23 has been moved downward to its resetting position the closure ofthe contacts 32 and 31 establishes a short circuit between the terminals of the-resetting magnet, and further operation of such magnet is therefore prevented until the lever 23 is again moved upward by reason of the operation of the switch hook 19. A further result accomplished-by the closure of the contacts 32 and 31 is that the impedance of the resetting magnet 31 at the calling substation-is removed from the line circuit during-talking.

The switch hook 1.9 is so disposed relatively to the contacts .17 and 18 that when in its depressed position which is its normal position under the weight of the receiver R, it engagesthe block of insulation18 carried by the spring 18, and thus separates the contacts 17 and 18 and interrupts the circuit through the primary winding of the induction coil :12.

Thewinding of theoperating magnet 85 is connected at one extremity to the spring 86 and at its opposite end it is joined by the line 85* to the line wire 1. The coils of this magnet are so wound that current in one direction will eifect its energization to actuate the armature 23 to open the contacts 86 and 87. The opening. of which cuts the magnet 85 outof the main line circuit until resetting magnet has been again energized- Assuming that the receiver R has been removed fromthe switch hook 19, as shown at the substation A, the register 22 is actuated and the contacts 1-7 and 18 areclosed, and thus in a manner well known in the art, the line :relay 7 is energized by the pulling up of its armature 34 against the contact 35, and a circuit is closed between the wires 8 and 9 through the line lamp36 to signal the operator at the exchange that a connection is desired. The current in the line at this time flows through the transmitter T, the primary winding of the induction coil 12 and through wires 20 and 21 in a direction which does not eflect the energizing of the resetting magnet 31. This condition continues until the direction of the current flow in the substation line isvreversed, through the extremities of the central office apparatus and the act of answering in by the called subscriber. l Vhen the called subscriber answers the current of the polarity flows through the resetting magnet 31 causing the armature 23 to be retracted setting the registering mechanism in position to be actuated. When the lever 23 reaches its lower or retracted position the contacts 32 and 31 are closed thus short-circuiting the magnet 31.

The reversal of current flow in the line circuit is accomplished, as follows:

The cord circuit herein shown consists of two strands 37, 38, extending from the tip and sleeve 39, 40 of the answering plug P to the tip and sleeve 41 and 42 of the calling plug P, respectively. The strands 37 and 38 have connected in them the listening key 43 andthe ringing key 44, and these strands are interrupted conductively, although continuous inductively by the condensers 45, 46 in a manner well known in the art. -An operators set 47 is provided in the usual manner, such set being connected with the listening key 43. I

The battery B has its negative terminal connected by the wires 8 and 48 with one terminal of the winding of the tip supervisory relay 49, the other terminal of which is connected by wire 50 with the answering end of the strand 37 The same terminal of the battery B is also connected by wire 51 with one terminal of the winding of the tip supervisory relay 52, the other terminal of which is connected with the calling end of the strand 37 by wire 53. The positive pole of the battery B is connected by wire 54 with one terminal of the winding of the sleeve supervisory relay 55, the other terminal of which is connected by wire 56 with the calling end of the strand 38. The same pole of the battery B is also connected by wires 54 and 57 with the back contact 58 of the armature 59 of the relay 55.

The armature 59 is connected by wire 60 with one terminal of the winding of the sleeve supervisory relay 61, the other terminal of which is connected by the wire 62 with the answering end of the sleeve strand 3S. A generator G is provided, and has its field winding 63 connected by wires 64 and 65 directly with the terminals of the bat tery B. The positive and negative brushes 66 and 67 of the generator are connected respectively by wires 68 and 69 with the positive pole of the battery B and the front contact 70 of the armature 59.

The armatures 71 and 72 of the supervisory relays 49 and 52 are normally in engagement with their back contacts 73 and 74, which are connected with the super visory lamps 75 and 76 respectively, the other terminals of these lamps being connected together by the wire 9 to the positive pole of the battery B. The armatures 71 and 72 are connected together by the wire 76 77, and are also connected by the wire 78 with the spring contact 79 of the plug seat switch S, the other member 80 of which is connected by wire 81 with the negative pole of the battery B.

As a result of the circuit connections above described, when the operator answers a call received by the flashing of the lamp 36 and inserts the answering plug P into the jack J, the line relay 7 is deenergized by the separation of the ack springs 3 and 4 from the contacts 5 and 6 respectively, and current is now supplied from the battery B through the supervisory windings 61 and 49 to the line wires 1 and 2 in the same direction as it was previously supplied through the springs 5 and 6, as a result of which no energization of the magnet 31 occurs, since the core 13 is magnetized in the same direction.

This condition continues until the called subscriber, after having been properly connected by the insertion of the calling plug P in the jack J, and operation of the signaling mechanism at the called substation, responds by removing his receiver from his switch hook. "When the called subscriber removes his receiver from the switch hook he closes a circuit through the substation apparatus, thus causing the energization of the relay 55. This results in pulling up the armature 59 and interrupting the circuit from the positive pole of the battery B through wires 57 and 60 to the winding of the supervisory relay 61, and closing a 5 path between the negative brush of the generator G through wire 69, contact 70, armature 59, and wire 60 to the same terminal of the relay 61. The potential developed by the generator G should be approximately 1 0 twice the potential of the battery B, and as a result current is caused to flow through the battery B in opposition to its voltage and the resultant voltage impressed upon the strands 37 and 38 is of about the same 1 5 value as the voltage of the battery B but in a reverse direction. The generator G is especially constructed so as to supply direct noiseless current to the substation circuit which is adapted for talking purposes, and by its flow through the primary winding of the induction coil 12 it reverses the polarity of the magnet 31, and since the contacts 32 and 31 are open and the contacts 17 and 18 are closed, the resetting magnet 31 is energized, thus setting the register 22, at the close ofwhich operation the contacts 32 and 31 are closed to prevent subsequent accidental operation of the magnet 31.

The armature 23 being set in the actuated position as a result of the current reversing in the line following the answering of the called subscriber remains in this position until the calling subscriber hangs or replaces his receiver upon the hook 19. By this act the spring 18 is closed in the engagement with the contact 18 and the current thereupon flows through the operating magnet from line wires 1 and 2 through the contacts 86- and 87. The energizing magnet 85 causes the armature 23 to be returned to its normal position and 'in so doing the previously established connection is recorded on the indicator 22.

From'the circuits above described it will be noticed that the supervisory lamps 75 and 76 are lighted when the apparatus at thecorresponding"substations is returned to im normal position by hangingthe receivers upon the hooks andthatflow of current through the supervisory lamps 75 and 76 is interrupted by the opening of the plug seat switch S, when the calling plug P is returned to its normal position.

From the'above it will appear that if the called subscriber does notrespond, although the registering mechanism at the calling substation has been actuated, the calling subscriber is not improperly charged because When he makes the next call, it will eifectno actuation of the registering mechanism, inasmuch as it Was not reset during the preceding calling operation. "In other words by my system, although a call may be registered, when the called party is not available, still the-charged call is "in effect credited since no advance of the registering mechanism is made for the next call which may be responded to by the called subscriber.

The arrangement of the meter operating mechanism'at the substation D is identical with that shown and described for substation A, the only difference being that in connection with the substation 'D the lever 23 is shown in its lower position and the switch'hook 19 isshown in its normal position supporting the receiver R.

I claim as my invention:

1. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations'to such ex change, a meter at one of such substations, an operating magnet for the meter'85, means controlled by the hook switch for energizing such magnet, a resetting magnet 31 for the meter, and means -59 controlled by the response of the called subscriber for reversing the direction of current flow in the line to actuate such resetting magnet.

2. In a telephone exchange system, the

combination of a main exchange, telephone lines extendmg from substations to such exchange, a meter at one of such substations,

an operating magnet for the meter, means controlled by the hook switch for energizing such magnet, a resetting magnet for-the meter, means controlled by reversal of the current inthe line for actuating such reset ting magnet, and means for locking the meter in either its operated'or set position.

3. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to suchexchange, a meter at one of such substations, an operating magnet forthe meter, means controlled by the hook switch for energizing such magnet, a resetting magnet for the meter, means controlled by reversal of the current in the line for actuating-such resetting magnet, means for closing a'shunt between the terminalsof the resetting magnet by its operation, and means for opening the actuating circuit of the operating magnet by its operation.

l. In a telephone exchange system, the combination of a main'e'xchange, telephone lines extending from substations to such exchange, a meter at-one of such substations, an operating magnet for the meter, means controlled by the hook switch for energizing such magnet, a resetting magnet for the meter, means controlled by reversal of the current in the line for actuating such resetting magnet, means for closing a shunt betweenthe terminalsof the resetting magnetby its operation, and means for opening the actuating circuit of the operating magnet'by itsoperation. 1

5. In a meter adapted for'use at a telephone substation, the combination of registering mechanism, means for electromagnetically operating the registering mechanism, and switch springs controlled by the operation of the actuating mechanism adapted to openthe-circuitof the operating mechanism by its operation, such springs adapted to retain the operating mechanism in its actuated position.

6. 'In a meter adapted "for use at a telephone substationythe combination of regis-' tering mechanism, an operating magnet for the register, a resetting magnet, means for interrupting the operative relation of the resetting magnet at the end of operation 'of the meter and means'a'utomatically actuated by the talking apparatus at the substation at the close of a conversation for actuating the operating magnet, reestablishing an opera'tive condition of the resetting magnet and opening the operating circuit of the operating magnet.

7. A meter adapted for use at a telephone substation, consisting in the combination of registering mechanism, a magnet foroperating such mechanism, a magnet for resetting the registering mechanism, switch springs adapted to close a shunt circuit between the terminals o'fthe "resetting magnet by the resetting operation, switch springs circuit through the operating magnet, and adapted to be operated by the actuation of interruption of the shunt circuit between the the operating magnet to open its operating terminals of the resetting magnet.

circuit, and means controlled by the return GARRISON BABCOCK. of the switch hook to its normal position for Witnesses:

energizing the operating magnet to cause ,RHEA G. SPONSELLER,

actuation of the meter, interruption of the ARTHUR KNEISEL.

Copies of this patent may be obtained for five cents each, by addressing the Qommissioner of Patents,

1 Washington, D. 0. 

